Railway car truck



y 1949- K. R. HAMMERSTROM 2,476,660

RAILWAY CAR TRUCK Filed Dec. 28,- 1945 5 Sheets-Sheet l July 19, 1949.

RAILWAY CAR TRUCK s Sheet-Sheet 2 Filed Dec. 28', 1945 mm an w W ma .m m m m 0 a M M m w Z 0. w m V A u e, m M 31;, N\ m$ QM MWD NM 7 MM, 6 gm I .N\ ha mm MN WN QN 6N N Patented July 19, 1949 RAILWAY CAR TRUCK Karl R. Hammerstrom, to United States Steel a corporation of Dela 14 Claims.

This invention relates to an improved railway car truck.

The invention has among its objects the provision of a railway car truck of improved construction characterized by safety at high speeds, flexibility, and good riding qualities.

A further object of the invention is the provision of a railway car truck of such design that a frame of much lighter cross section than formerly possible may be used.

A further object is the provision of such truck which, while being flexible so that it yields when one or more Wheels pass over high or low spots in the tracks, is inherently self-squaring and self-aligning.

V These and further objects of the invention will be more fully apparent in the following description.

The invention willbe more readily understood by reference to the accompanying drawings, in which:

Figure 1 is a view of a railway car truck made in accordance with the present invention, said view being partly in plan and partly in horizontal cross section, the section being taken along the line I-I in Figure 2;

Figure 1A is an enlarged view in section of the portion of Figure 1 showing the motion dampening device;

Figure 2 is a view in vertical cross section through the truck, the section being taken along the line II-II in Figure 1;

Figure 3 is a view in vertical cross section through the truck, the section being taken along the line III-III of Figure 1;

Figure 4 is a view in horizontal cross section of a portion of the truck side frame, the transoms, and the spring seat attached to the latter, the springs being omitted, the section being taken along the line IVIV of Figure 2;

Figure 5 is a view in vertical section through a broken section of the truck side frame and the fr arne engaging portion of a transom, in a modification of the structure shown in Figures 1 to 4, inclusive;

Figure 6 is a view in vertical cross section through the structure shown in Figure 5, the section being taken along the line VIVI in Figure 5;

Figure 7 is a view in horizontal cross section through the structure shown in Figures 5 and 6, the section being taken along the line VIIVII in Figure 6;

Figure 8 is a view partly in elevation and partly in vertical section of a broken portion of a Pittsburgh, Pa., assignor Corporation of Delaware,

ware Application December 28, 1945, Serial No. 637,626

truck side frame showing a modified structure of the motion dampening device and its mode of attachment to the frame;

Figure 9 is a view in vertical section through the structure shown in Figure 8, the section be ing taken along the line IX-IX in Figure 8;

Figure 10 is a view in horizontal section, the section being taken along the line X-X in Figure 8, the motion dampening members being omitted;

Figure 11 is a view in horizontal section showing a spring seat device which is a modification of that shown in Figure 4;

Figure 12 is a view in elevation of a motion dampening side friction plate; and

Figure 13 is a view partly in elevation and partly in vertical section showing the relationship between the spring seat supported by the transoms, the springs, and the bolster, when the bolster has shifted laterally with respect to the transoms.

The railway car truck shown in the drawing and described in the following specification is of the four-wheel type adapted to fit a standard gauge freight car. It is to be understood, however, that because of its flexibility, safety at high speeds, and good riding qualities, it may be used to advantage on various types of cars on different gauges of track. The truck shown consists of two parallel side frames 2 mounting journal boxes 4 at the ends thereof for the reception of axles 6 having flanged wheels 8 aflixed thereto.

The side frames shown are substantially simi- I lar to those employed in the A. A. R. standard freight car truck, with the exception of the central portion thereof which includes a novel load bearing means which is one of the features of the present invention.

The central portion of each side frame mem- 0 her 2 is provided with a centrally located side frame window opening l0 formed between the top chord l2 of the frame, the bottom chord I4, and the sides l6 of the frame Window opening. Each side I6 is provided with a seat generally designated H for the reception of transom members, each such seat having a bottom l8 sloping downwardly in the direction of its adjacent bearing journal in the plane of the paper in Figure 2, and curved on a relatively long radius in the plane of the paper in Figure 3 to form a shallow socket. The seat is completed by the substantially plane vertical side wall l9. Seat I! preferably is located, as shown in Figure 2, so that the bottom of the seat l8 lies with its center, which aevaooo coincides in this particular design with the center of pressure, at least substantially coinciding with the vertical line C- from the point 0, which is the intersection of the neutral axes A-0 and 3-0 of the bottom chord l4 and the diagonal chord 20 at the bottom of frame 2, respectively. Since seats I] bear the full weight of the car body and load, as will be more fully apparent hereinafter, such design imposes forces upon bottom chord ll of the frame which are wholly in tension, thereby allowing such chord to be of much lighter section than would be possible if it were forced to act as a beam, as it is in designs, wherein the car body is carried, through the medium of the car springs, on such bottom chord member.

The two opposite parallel side frame members 2 are held together in parallel relationship by the two transverse transoms 22, the outer ends 24 of which haves shapes complementary to the seats I] of the frames. Thus, portions 24 of the transoms are provided with a sloping bottom 25 and a vertical 'side' wall 28 which engage the corresponding portionsof the seat. The transoms are held from excessive movement transversely of the members 2 by means of the outer and inner gibs 30 and 32, which engage the outer wall portions of seats H, as shown in Figure 1. The vertical side wall 28 on the end of each transom is provided with an outwardly projecting boss 34 which extends through a hole in the vertical side wall of the seat, the hole being of somewhat larger diameter than the boss, and is secured therethrough by means of the transverse pin 35 placed through a hole in the outer end of the boss and on the outside of the vertical wall on the seat. Such construction is convenient for holding the transoms in the side frames when the truck is being assembled, but since the transoms are held in the frames by the weight of the car body when the truck is assembled and connected to such body, the boss and pin are not necessary if suitable jigs are employed in the assembly. A car truck having similar means for connection of the transoms to the frames is shown and described in the copending application of Hammerstrom, entitled "Railway car truck, Serial No. 637,627, filed December 28, 1945.

Each transom member is provided near its outer end and at the bottom thereof with a depending bracket 38, shown in Figures 2 and 3, having sockets 40 therein for the reception of the outwardly and downwardly, projecting fingers 43 on the spring seat 42. In the modification shown in Figures 1 to 4, inclusive, two independent spring seats 42, each mounting two spring sets side by side, are Provided. as shown more clearly in Figure 4. Each spring seat is provided with a central boss 44 and an upstanding rim 46, the inner spring 48 being received about the boss and the outer spring 50, which is telescoped thereover, being received and held by the upstanding rim.

The bolster 52, which is av transverse beam member lying between the transoms and to which the bottom of the car body is attached, is provided with a corresponding downwardly facing spring seat 54 having a similar boss and rim construction for retaining the upper ends of the inner and outer springs thereon. As shown in Figure 3, the body center plate 60 of the car is attached to bolster 52 and prevented from being disengaged by means of guards 62. The bolster, and consequently the car body, are free to move a limited amount laterally with respect to the truck side frames. Figure 13 shows the conditions existing at the springs and spring seats when the bolster has shifted to the right. By reason of the construction of the spring seats on the transoms in pairs, as shown in Figures 4 and 13, they are free to rock slightly on their supporting bracket 38, and thus springs 48 and 50 are bent only slightly laterally as the result of the shifting of the bolster.

Lateral motion of the bolster with respect to the transom is limited by means of the outwardly facing inclined stop members 52 mounted on the bottom of the bolster, members 62 confronting similarly inclined stop members 64 upon the transoms. As a result of such structure, the extent of lateral shifting of the bolster becomes progressively less as the supporting springs are compressed upon an increasing load in the car; this results in holding the torsional stresses on the springs within safely allowable limits. In addition, the inclined face on the stops-tends to dampen the force of impact at contact of the stops.

The truck is provided with means for suporting the brake system for the car truck. Such means include brake hanger brackets 66, pro- :lecting from the outer upper corner Of each transom at the end thereof, the dead lever fulcrum bracket -68 on one transom, the bottom truck lever connector safety strap 10, which is connected by means of lugs on the bottom of the transom, and the brake beam supports '15, each of which is attached to lug 12 on the depending'bracket 38 on the transom, and is further supported upon a second lug 14 on such bracket.

As a result of the design of the car truck above described, such truck possesses inherent selfsquaring tendencies while having sufflcient flexibility to allow it to ride smoothly over inequalities in the track with substantially uniform wheel loads. As can be seen, the transoms are attached to the side frame members solely by means of the engagement between seat ll on the frames and the ends 24 on the transoms. Such connection is not rigid, since the transom may move a limited amount either vertically or laterally (parallel to the frames 2) of the seat in response to high or low spots in the track, but the weight of the car body and the weight of the load therein insures that portion 24 of the transoms will always inherently seek to return to the position in seat I! in which they are most firmly seated, in which position they hold frames 2 parallel and square to the track. The amount of force applied between the transoms and the side frames in keeping the trucks square is determined by the amount of slope of the bottom of the seat l8. It is obvious that such slope may be varied if desired, for cars having bodies of different weights or designed to carry different oads.

In order still further to stabilize the car and to dampen motion of the body in both vertical and lateral directions, the truck is provided with a motion dampening device shown more clearly in Figures 1A, 2, and 3. Each outer end of the 15 frame.

bolster 52 is provided with a projecting bracket 18 having a horizontal slot therethrough. Positioned one on each side of bracket 18 are two upright friction plates 82 affixed to the top of bottom chord M of the frame by means of bolt 84 passing through holes in the bottom of plates 82 and through spaced, ears 86 attached to the The upper ends 81 of friction plates 82 are tapered laterally and are received in a correspondingly shaped socket 88 in the top chord I2 of the frame and extending longitudinally thereof. The spacing of ears 86 is such relative to the thickness of bracket I8 and plates 82, and the length of socket 88 is such that plates 82 may travel with the bolster longitudinally of the frame. Friction plates 82 are provided with a vertical slot 89 whose center corresponds to the center of the horizontal slot in the bracket 10 when the car is normally loaded and the bolster is in the central position with respect to the transoms. A bolt 90 having a' squared inner section to prevent its turning passes through slots 80 and 89 and'through two external friction plates 92 positioned one on each side of the vertical friction plate. The friction plates are held together under a predetermined pressure by means of spring 94 about the outer shank of bolt 90, the spring being held under a selected compression by nut 96.

Such vertical and lateral motion dampening device creates a limited resistance to vertical and lateral motion between the truck bolster, whichcarries the car, and the trucks. The design of the motion dampening device shown is such that the resistance imposed against vertical motion is twice that imposed against lateral motion. This follows from the fact that, upon motion of bracket I8 laterally with respect to vertical friction plates 82, relative motion takes place merely between the bracket and the vertical plates; whereas upon vertical motion of the bracket, there is relative travel between bracket '18, external friction plates 92, and the vertical friction plates 82. Thus in vertical travel there is employed in the device a motion retarding frictional area which is twice that utilized in opposing lateral motion. It has proved desirable from the standpoint of flexibility to allow the car body to move laterally somewhat more freely than it moves vertically, and so such relationship between resistance imposed against lateral motion and that imposed against vertical motion by the dampening device is advantageous. It is obvious, however, that in some designs a relationship different from the two to one ratio of frictional areas may prove desirable; this may be attained by use of a plurality of bracket friction plates on the bolster and a suitable number of vertical friction plates.

The railway car truck of the present invention is capable of numerous variations in various details. Some of these modifications are shown in Figures 5 to 11, inclusive. In Figures 5, 6 and 7, there is shown a modified'construction of the transom receiving seat in the side frame and the seat engaging portion of the transom. In these figures, parts which are similar to those shown in Figures 1 to 4, inclusive, are designated by the same numerals primed. The seat I I, in this instance, consists of a horizontal bottom portion I8 and a vertical side wall I 9'. The center of the bottom of the seat, as before, lies at least substantially on the vertical line C'O' from the point of intersection of the neutral axes 'A'O and B'O' of the bottom and diagonal chords of the frame, respectively. Transom 22' is provided with a seat engaging portion 24' having bottom gibs I08 and vertical lateral gibs I I0 to position it centrally of the seat. The transom is caused to be restored to a position in which portion 24 fully engages seat I1, and thus the truck side frames are automatically squared, after the truck has been flexed as by reason of unevenness in the track, by means of the compression spring 6 I I6 positioned around the outer shank of bolt II4 which passes through the side walls of the transom and a suitably located hole on the vertical side wall of the seat. The force imposed upon the transom to restore it in its fully seated position in the frame may be varied by the extent with which the nut I I8 is screwed down on the bolt.

In Figures 8, 9, and 10, there is shown a modification of the vertical and lateral motion dampening device. As there shown, instead of being mounted pivotally on the botton chord of the frame, the two upright friction plates I24 are slidably mounted in sockets at their upper and lower ends. Plates I24 are contacted at the bottom by guide member I26 which is received within a, socket in bottom chord I20 of the frame, said socket having upstanding ears I32 at the sides thereof. A compression spring I28 is positioned between the bottom of the guide member and the bottom surface of the socket. The upper ends I36 of the upright friction plates are rounded as shown in Figure 9, and are received in a correspondingly shaped elongated socket I34 extending longitudinally of the frame in theupper chord I22 thereof. Such structure allows the vertical plates of the dampening device to shift freely longitudinally of the frame, and thus prevents it from injury due to permissible shifting of the car bolster longitudinally of the frame. In addition, spring I28 holds the plates I24 in contact with' theupper chord I22 to insure instant frictional resistance to lateral motion.

In Figure 11, there is shown a modification of the truck spring seat. In such alternative structure, the spring seat on one side of the truck is made unitary rather than in two pieces, as contrasted with that shown in Figure 4. Such spring seat is provided with four central bosses I02, an upstanding rim I04, and a partition I06 having a central portion curved, as shown, to position the outer spring between it and the corresponding curved corner 'of the spring. The spring seat is further provided with outwardly and downwardly projecting fingers I00 which are received in the sockets in the depending brackets 38 on the transoms. Use of the integral spring seat shown in Figure 11 requires that the springs 48 and 50 sustain higher torsional forces than does use of the spring seats shown in Figure 4, 50 since the bottom spring receiving members do not tilt in response to lateral motion of the car body. The latter design, however, is permissible in certain instances, particularly where loads are not high and where economy is desired.

Having thus fully described the railway car truck of the present invention, I desire to claim as new the following.

I claim:

1. A railway car truck comprising two parallel truck side frames, each side frame having a load bearing seat thereon on each side of the longitudinal center of the frame, each seat being formed by a substantially horizontal bottom surface and a generally vertical side wall, a pair of 5 load bearing transoms having seat engaging ends of a shape complementary to the seats shiftably positioned in the seats. resilient means constantly urging the seat engaging end of each transom into its seat so that its side wall seeks to remain in contact with the side wall of the seat, and means on said side frames and transoms for maintaining the side frames in substantially parallel relationship while allowing limited shifting of the transoms longitudinally of the frames.

2. A railway car truck comprising two parallel truck side frames, each side frame having a load bearing seat thereon on each side of the longitudinal center of the frame, each seat being formed by angularly disposed surfaces extending transversely of the frame, said surfaces meeting in a line lying below the remainder of the surfaces, a pair of load bearing transoms having seat engaging ends of a shape complementary to the seats shiftably positioned in the seats, and means on said side frames and transoms for -maintaining the side frames in substantially parallel relationship while allowing limited shifting of the transoms longitudinally of the frames.

3. A railway car truck comprising two parallel truck side frames, each side frame having a central window therein, each window having a load bearing seat on each side thereof, each seat being formed by angularly disposed surfaces extending transversely of the frame, one of said surfaces being curved transversely of the frame to form a socket, said surfaces meeting in a line lying belowthe remainder of the surfaces, a pair of load bearing transoms having seat engaging ends of a shape complementary to the seats shiftably positioned in the seats, and means on said side frames and transoms for maintaining the side frames in substantially parallel relationship while allowing limited shifting of the transoms longitudinally of the frames as a result of movement of the two side frames relatively to each other.

4. A railway car truck comprising two parallel truck side frames, each side frame having a central window therein, each window having a load bearing seat on each side thereof, each seat being formed by a substantially vertical side wall and a bottom making an acute angle with the side wall, both side wall and bottom being of appreciable area and, extending transversely of the frame, a pair of load bearing transoms having seat engaging ends of a shape complementary to the seats shiftably positioned in the seats, and means on said side frames and transoms for maintaining the side frames in substantially parallel relationship while allowing limited shifting of the transoms longitudinally of the frames as a result of movement of the two side frames relatively to each other.

5. A railway car truck comprising two parallel truck side frames, each side frame having a generally horizontal top chord, a bottom chord parallel thereto, vertical members on each side of the longitudinal center of the frame connecting the top and bottom chords, and diagonal chords between each of the points of intersection of the bottom chord and the vertical members and the top chord, each vertical member having a load bearing seat thereon, each seat being formed by angularly disposed surfaces extending transversely of the frame, said surfaces meeting in a line lying below the remainder of the surfaces, a pair of load bearing transoms having seat engaging ends of a shape complementary to the seats shiftably positioned in the seats, the seats being so located in the vertical members that the center of pressure between the'transom and seat lies on a vertical line passing through the intersection of the neutral axes of the bottom and diagonal chords, and means on said side frames and transoms for maintaining the side frames in substantially parallel relationship while allowing limited shifting of the transoms longitudinally of the frames as a result of movement of the two side frames relatively to each other.

6. A railway car truck comprising two parallel truck side frames, load bearing means connecting the side frames to maintain them in parallel relationship comprising a plurality of transoms,

at least one vertical socket near the end of each transom, the sockets on the two transoms at each truck side frame lying in a plane parallel to the frame, a spring seat at each truck side frame, said spring seat having a projection at each end thereof loosely fitting into a socket on each of the transoms, and a plurality of sets of coil springs on each spring seat, said spring sets lying parallel to the side frame for supporting a load bearing member of the car body, whereby the spring seats may rock on their projections on the sockets when the car body shifts laterally with respect to the truck.

7. A railway car truck comprising two parallel truck side frames, each side frame having a load bearing seat thereon on each side of the longitudinal center of the frame, each seat being formed by angularly disposed surfaces extending transversely of the frame, said surfaces meeting in a line lying below the remainder of the surfaces, a pair of load bearing transoms having seat engaging ends of a shape complementary to the seats shiftably positioned in the seats, means on said side frames and transoms for maintaining the side frames in substantially parallel relationship while allowing limited shifting of the transoms longitudinally of the frames, means near the ends of each transom providing a support, a spring seat at each truck side frame engaging and supported by the supports on the corresponding ends of the transoms, and springs on the spring seats for engaging and supporting a load bearing member of the car body.

8. A railway car truck comprising two parallel truck side frames; each side frame having a load bearing seat thereon on each side of the longitudinal center of the frame, each seat being formed by angularly disposed surfaces extending transversely of the frame, said surfaces meeting in a line lying below the remainder of the surfaces, a pair of load bearing transoms having seat engaging ends of a shape complementary to the seats shlftably positioned in the seats, means on said side frames and transoms for maintaining the side frames in substantiallyparallel relationship while allowing limited shifting of the transoms longitudinally of the frames, at least one vertical socket near the end of each transom, the sockets on the two transoms at each truck side frame lying in a plane parallel to the frame, a spring seat at each truck side frame, said spring seat having a projection at each end thereof loosely fitting into a socket on each of the transoms, and a plurality of sets of coil springs on each spring seat, said spring sets lying parallel to the side 5 fr'ame for engaging and supporting a load bearing member of the car body, whereby the spring seats may rock on their projections on the sockets when the car body shifts laterally with respect to the truck.

9. A railway car truck comprising two parallel truck side frames, each side frame having a load bearing seat thereon on each side of the longitudinal center of the frame, each seat being formed by angularlydisposed surfaces extending 7o transversely of the frame, said surfaces meeting in a line lying below the remainder of the surfaces, a pair of load bearing transoms having seat engaging ends of a shape complementary to the seats shiftably positioned in the seats, means 75 on said side frames and transoms for maintainto the frame, a spring seat at each truck side frame, said spring seat having a projection at each end thereof which support the-spring seat by engagement with the socket on each of the transoms, the engagement between the projections and sockets being loose laterally, and a plurality of sets of coil springs on each spring seat, said spring sets lying parallel to the side frame for engaging and supporting a load bearing member of the car body, whereby the spring seats may rock on their projections on the sockets when the car body shifts laterally with respect to the truck.

10. A railway car truck comprising two parallel truck side frames, transoms connecting the side frames to maintain them in parallel relationship, a spring seat on the ends of each transom at each truck side frame, a bolster adapted to be connected to the bottom of the car body, coil springs between the bolster and the spring seats, and stop means between the bolster and at least one of the transoms for limiting transverse movement of the bolster with respect to the transoms, the stop means being so constructed and arranged that the amount of transverse movement permitted the bolster becomes progressively less as the bolster moves vertically downwardly.

11. A railway car truck comprising two parallel truck side frames, transoms connecting the side frames to maintain them in parallel relationship, a spring seat on the ends of each transom at each truck side frame,.a bolster adapted to be connected to the bottom of the car body, coil springs between the bolster and the spring seats, and stop means between the bolster and at least one of the transoms for limiting transverse movement of the bolster with respect to the transoms, the stop means comprising a pair of abutments on at least one of the transoms and a pair of cooperating abutments on the bolster, one of the pairs being located inwardly of the other toward the center of the truck, the confronting faces of cooperating abutments being inclined from the vertical so that as the bolster moves vertically downwardly the horizontal distance between the faces of the cooperating abutments grows less.

12. A railway car truck comprising two parallel side frames, transoms connecting the side frames to maintain them in parallelism, a spring seat on the ends of each transom at each truck side frame, a bolster adapted to be connected .to the bottom of the car body, coil springs between the bolster and the spring seats, and means for dampening the lateral and vertical motion of the bolster comprising at least one substantially fixed friction plate attached to each side frame, at

least one projecting member on each end of the bolster having sliding frictional contact therewith both laterally and vertically, and means to urge the projecting member against the fixed friction plate.

13. A railway car truck comprising two parallel side frames, transoms connecting the side frames to maintain them in parallelism, a spring seat on the ends of each transom at each truck side frame, a bolster adapted to be connected to the bottom of the car body, coil springs between the bolster and the spring seats, and means for dampening the lateral and vertical motion of the bolster comprising a pair of parallel substantially fixed friction plates attached to each side frame, a fiat projecting member on each end of the bolster passing between and in contact with the parallel friction plates at the corresponding end thereof, a pair of fiat movable friction plates on the outer faces of the fixed friction plates, each of the projecting members on the bolster having a horizontal slot therein, the fixed friction plates having vertical slots therein, and the outer movable friction plates having holes therein, and means holding said friction plates and projecting members together with a predetermined force, said holding means passing through the holes in the outer friction plates and the slots in the fixed friction plates and the flat projecting member.

14. In the railway car truck set out in claim 13, the pairs of parallel friction plates being mounted vertically on the side frames so as to be fixed laterally of the side frame but to have substantial freedom of movement longitudinally thereof, so as to move longitudinally of the side frame with the projecting members on thebolster.

KARL R. HAMIVIERSTROM.

REFERENCES CITED The following referemces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 632,425 'Player Sept. 5, 1899 666,661 Goltra. Jan. 29, 1901 1,130,665 Bullock Mar. 2, 1915 1,916,082 Somervell June 27, 1933 2,061,767 Hobson Nov. 24, 1936 2,168,293 Kiesel Aug, 1, 1939 

